Roll-up ladder



ug- 10, 1965 Q. v. WAGNER ETAL 3,199,627

ROLL-UP LADDER Filed April 17, 1962 5 Sheets-Sheet 1 ug- 10, 1955 Q. v. WAGNER ETAL 3,l99,627

ROLL-UP LADDER 5 Sheets-Sheet 2- Filed April 17, 1962 ug- 10, 1965 Q. v. WAGNER ETAL 3,l99,627

ROLL-UP LADDER 5 Sheets-Sheet 3 Filed April 17, 1962 amn.

WNTORS.

ug- 10; 1965 Q. v. WAGNER ETAL 3,199,627

ROLL-UP LADDER 5 Sheets-Sheet 4 Filed April 17, 1962 INVENTOR. MW, BY W /l MZ/F/VK ug- 1G; 1965 Q. v. WAGNER ETAL 3,l99,627

ROLL-UP LADDER Filed April 17, 1962 5 Shee'hS-Shee'rl 5 INVENTORS United States Patent O 3,l99,27 ROLL-UP LADDER Quentin V. Wagner and Hehnut W. Dettlofi, Bellevue, hio, assignors to Aladdin Ladders, Inc., a corporation of hio Filed Apr. 17, 1962, Ser. N 188,291 7 Claims. (Cl. 182-163) This invention relates to an articulated ladder, that is a ladder which is constructed of a plurality of interconnected sections adapted to be rolled up into a compact spiral and to be extended into operable condition and held in that extended condition with the requisite degree of ruggedness and stability.

A ladder of the type to which the invention is directed has considerable utility, particularly to -those persons engaged in occupations requiring the transportation of a ladder from place to place. Normally it is impractical for such persons to carry an extended ladder on their automobiles and as a consequence they are required to purchase a truck which has little utility for them other than for the transportation of their ladder. A ladder which can be coiled into a compact package on the other hand can be carried in the trunk of a car.

A roll-up ladder has attributes which make it valuable to still other people for, in Iolling up into a compact package, it is adapted for storage in small areas which would otherwise be unsuita'ole for ladder storage. Additionally, it is easily carried by a person around tight corners and in crowded conditions where an extended ladder would be somewhat unmanageable.

There are a number of features which are necessary for the commercial success of such a roll-'up ladder. It is of paramount importance for example that the ladder be braced in a substantial manner so that, when extended, a person standing on the ladder has complete assurance that it will not Collapse. Further, the ladder must have its complexity reduced to the point that it can be extended and rolled up With a minimum of effort and a minimum of operations.

It has been an objective of the present invention to provide a ladder having the attributes of strength in extended position as well as minimal complexities.

In describing the ladder of the invention for convenience reference will be made to the front and rear sides of the ladder. The rear side is that side Which faces the structure against which the ladder is leaned and the front side is the opposite side. Similarly, reference will be made to the top and bottom of the ladder. It should be understood that in most instances, unless a critically has been asserted for the location of an element with respect to one or the other end, the location of the elements at either end is interchangeable.

It has been an objective of the invention to provide a roll-up ladder Which comprises a plurality of hollow sections having positive bracing means cooperating between adjoining sections for bracing the ladder from front to rear when the ladder is in its extended position and providing lateral bracing for the side rails of the ladder.

It has been another objective of the invention to provide a ladder comprising a plurality of hollow rail sections and a cable passing through the rail sections with improved means for applying tension to the cable to draw the sections tightly together when the ladder is extended.

In a ladder of the type described above the hollow sections receive the tightening cable passing therethrough as Well as elements providing the bracing and elements providing an aligning and a hinging function. To eliminate the interference of the elements with respect to each other, the invention provides for the division of the hollow sections into two longitudinally extending hollow porice tions, the cable and bracing aligners being maintained in one hollow portion separated from the remaining elements. Additionally, and in accordance with the preferred form of the invention, the aligners are formed of sheet metal bent to a U-shaped configuration with the tensioning cable passing between the legs of the U-shaped aligner. By coniningV the cable within the aligner, all possibility of the cable becoming snarled with the aligner when it is not under tension has been eliminated.

The aligner elements are disposed within the hollow sections and overlap each other, each aligner element extends between three adjacent sections and is configurated to permit each section to pivot with respect to an adjoining section through a limited angle for rolling the ladder. The aligner elements prevent any pivoting of the sections in the reverse direction and thereby maintain the ladder in its erect position.

It has been another objective of the invention to provide a ladder of the type described in Which each section has an abutment which projects into an adjoining section, each side rail also having a longitudinal strap of spring steel which extends from one end of each rail to the other adjacent to the abutments. The abutments form hinge members about which each section pivots with respect to the adjoining section When the ladder is rolled up and maintain the sections in alignment when the ladder is extended. The spring steel strap serves as a guide to bring the abutments into proper engagement with the adjoining sections when the ladder is extended and its resilience facilitates the unrolling of the ladder when it is to be used.

These and other objectives of the invention will become more readily apparent from the following detailed description taken in conjunction with the acccmpanying drawings in which:

FIG. l is a front elevational view of a ladder shown in its extended position;

FIG. 2 is a side elevational view of a ladder partially rolled up;

FIG. 3 is a side elevational view of a ladder completely rolled; i

FIG. 4 is a fragmentary perspective view partly in section of the invention to show the cooperation of the principal elements;

FIG. 5 is a fragmentary View partly in section showing principally the bracing elements associated with the cooperating rail sections;

FIG. 6 is a view similar to FIG. 5 showing the elements in rolled up condition;

FIG. 7 is a cross sectional view taken along lines 7-7 of FIG. 5;

FIG. 8 is a fragmentary side elevational view of the ends of a rail member;

FIG. 9 is a disassmbled perspective view of the connection of a rung to a' rail section;

FIG. 10 is a fragmentary rear elevational view partly in section of the connection of a rail section;

FIG. 11 is a rear elevational view of the bottom rung of the ladderk with the Operating levers removed for clarity;

FIG. 12 is a cross sectional view taken along lines 12-12 of FIG. 11 with the Operating levers replaced;

FIG. 13 is a view similar to FIG. 11 showing an intermediate stage of operation of the Operating levers; and FIG. 14 is a view similar to FIG. ll showing still another intermediate stage of the operation of the levers.

Referring to the drawings, a ladder constructed in ac.- cordance with the invention is shown at 15 in FIG. 1. That ladder comprises a pair of side rails 16 and 17 which are spaced from each other byga plurality-of rungs 18. It should be noted that the rungs are of descending grad-V uation in length from the bottom to the top of theV ladder so that the side rails 16 and 17 are not precisely parallel anestesi' to each other. Becauseof the taper of the ladder from the bottom to top, when the ladder is rolled up, the top portion of the ladder will roll within the side rails at the lower portions of the ladder to form a more compact package. This telescoping relationship is illustrated in part by FIGS. 2 and 3 wherein the rolling up of the ladder is illustrated. It can be observed from FIG. 2 that as the ladder is rolled, the top end of the ladder indicated at 19 ts between the side rails 16 and 17. A ladder completely rolled up is illustrated in FIG. 3.

The ladder elements and their relative positions With respect to each other is illustrated generally in FIG. 4. Each of the ladder side rails 16 and 17 is substantially identically constructed as a mirror image of the other. Each rail has as its principal elements a plurality of individual sections 21 Which preferably are extruded from aluminum. The sections are hollow and each has a thin fiat hollow portion 22 and a second hollow portion 23 which is rearward of the hollow portion 22. Referring to the left rail 17 as viewed in FIG. 4, passing through the hollow portion 22 of each section is a flexible cable 24 which is secured at its upper end 25 by a pair of set screws 26 which permit the slack in the cable to be taken up slightly in the event that the cable elongates after continued use (FIG. 8). The lower end portion 27 of the cable 24 passes around a pulley 28 which is rotatably mounted on the lowermost rung 29 of the ladder. The end of the cable is fastend to a slidable member of block 31 which is slidably mounted in a channel 32 in the rung 29.

The cable on the right side of the Vladder as viewed in FIG. 4 is similarly connected at its upper end and is connected at its lower end to a slidable block 31 in a channel 33 adjacent to the channel 32 in rung 29. A pair of levers 34 and 35 are pivoted at their ends 36 to the blocks 31 and are pivoted to each other at 37 intermediate their.

ends to form a double throw lever system. The levers may be swung from the position shown in FIG. 4 to an opposite position carrying their respective blocks to the opposite sides of the lower rung 29 thus relieving the tension on the cable 24. For complete assurance that the Operating levers 34 and 35 Will remain in the position illustrated in FIG. 4, a latch such as is indicated at 40 may be pivoted as at 41 to the bottom rung to be swung into position overlying the lever 35.

Also extending the length of the ladder and passing through the second or rearward hollow portion 23 of each section of each rail is a strap 42 which is preferably made of spring steel. The strap 42 has a lower end 43 which is wrapped about a foot 44 of the ladder and Secured thereto by a screw 45 (FIG. 8). The strap 42 has an upper end 47 which is bent around a pin 43 and Secured in a notch 49 formed in a block 50 at the upper end of the ladder. The strap 42 serves to guide the sections 21 into proper alignrnent With each other as will be described below. Addtionally, being made of spring steel, the strap facilitates the unrolling of the ladder when it is to be converted to its extended position.

Each section has an abutment or stud fixed in the lower end of the hollow portion 23 and projecting downwardly into the upper end of the hollow portion 23 in an adjoining section. The stud is formed with a curved surface as at 56 which, when carried by its section during rolling and unrolling permits it to pivot with respect to the adjoining section without interference from the walls of the hollow portion 23. The stud is spaced from the inner surface of the rearward wall 57 of a hollow portion 23 by an amount slightiy greater than the thickness of the Strap 42. Thus the sections 21 carrying their studs 55 are permitted to slide relatively freely with respect to the strap 42. It should be understood that the position of the studs 55 could be reversed from the lower ends to the upper ends of their sections 21 without affecting their operation.

A plurality of transverse braces or aligners 60 are spaced along the length of each rail and are positioned Within the thin hollow portion 22. Each aligner is formed of sheet material which is bent .into a U-shaped configuration having legs 63 and 64 paralleling the major walls of the hollow portion 23. One leg 63 has a lower integral lug 61 and the other leg 4 has an upper integral lug 62. Both lugs extend the full depth of the hollow portion 22 to provide the required front to rear bracing when the ladder is in use. The aligners have a recessed central portion between the lugs to accommodate the rearward hollow portion of the alternate sections when the aligners move relative to the sections 21 from the position of FIG. 5 to the position of FIG. 6 asthe ladder is rolled. The relationship of the aligner dimensions to the dimensions of hollow portion 22 is such as to prevent over rolling which would flex strap 42 beyond its elastic limit. In other words, the aligner prevents the sections from pivoting through an angle greater than approximately 50.

The lower lug 63 is pivotally Secured to a section 21 by means of a screw or rivet 65. The screw or rivet must terminate inside hollow portion 23 as flush as possible against lug 61 to permit cable 24 to pass freely by the screw or rivet 65. The aligner has an intermediate portion 66 which straddies the adjoining section 21. The upper lug 62 and upper portion of the aligner 60 project into the next succeeding section 21 (FIG. 5). The next succeeding section has an aligner 69 pivoted to it with its lower lug 61 overlying the upper lug 62 on the lower aligner. Thus throughout the length of the ladder there is a complete continuity of aligners which serve to brace the ladder against iexure in a lateral direction and which brace the ladder against Collapse from the front to rear when it is in use.

Referring to FIG. 7, it can be seen that the aligner has an outside surface which confcrms to the inside surface of the hollow portion 22 in which it is disposed. The outside radios of the bight portion of the aligner is substantially the same as the inside radius of the end of the hollow portion in which the alisner is disposed. The aligner is transverseiy dimensioned With respect to hollow portion 22 to provide a very snng fit between the sections 21 and their aligners ett which not only eliminates rattling of the parts With respect to each other,

' but more important, substantially eliminates any tendency of the rails 16 and 17 to bend laterally.

It should also be observed from FIG. 7 that the cable 24 normally lies within the confines of the legs of the U-shaped aligner member. It is also confined by a wall 67 between the hollow sections 22 and 23 from becoming tangled with the hinge studs 55 in the hollow portions 23.

The aligners 60 collectively extend from the top of the ladder to the bottom of the ladder in the manner described above. Every sixth aligner, for example, may be provided with a stud 63 as shown in FIGS. 5 and 6, the stud 58 spacing the cable 24 outwarly toward the front of the ladder to provide a leverage or improved direction of the application of the force of the cable on the sections to facilitate the straightening of the ladder to the extended position.

The manner of attaching the rungs 13 to the rails 16 and 17 is illustrated in FIGS. 9 and 10.

Each of the sections has an inwardly directed flange 7 having a longitudinal groove 71. Each rung is slotted as at 72 in each end thercof so as to receive the longitudinal flange 70. The tianges 'iii are also slotted as at 73. These slots receive lugs 74- formed in the rungs by the slots 72. The lugs engage flange edges 75 created by slots '73 and support the rungs against sliding down along the rails. On every fonrth section, for example, a rung is mounted by sliding the fiange into the slot 72 and the metal is deformed by crimping it into longitudinal grooves 71 as at '76 so as to secure the rung securely to the section 21.

In operation of the ladder, let it be assumed that the ladder is in the rolled up condition of FIG. 3. When in this condition, the levers 34 and 35 are in a position reladng the tension on cables 24, that is, opposite to the position shown in FIG. 12. The ladder is held in the rolled up position by a resilient Strap 81 which is tied at its ends 32 through holes in the flanges 79 (FIGS. 4 and 11). A hook 33 is securcd to the strap 81 intermediate its ends and is adapted to engage a rung on the nearest section 21 when it is in rolled condition.

The rolling of the ladder takes up approximately twelve inches of slacl: in cable 24 (depending on the overall length of the ladder), the slack having been provided to avoid the cable,s preventing the rolling of the ladder. The double throw lever systern' which utilizes two slidable blocks 31 each traversing substantially the full length of the bottom rung permits the use of a maximum amount of slack necessary for twelve foot, sixteen foot, and even longer ladders.

The first step is to unhook the hook 33 so as to free the ladder for unrolling. A gentle shove on the ladder coupled with the spring action of the strap 42 will cause the ladder to roll out flat. Extending the ladder leaves cable 24 with excess slack as shown at S4. When the ladder is flat and in its extended condition, the levers 34 and 35 are swung through the positions shown in FIGS. 14 and 13 consecutively to the position shown in FIG. 12.

In Swinging the levers 34 and 35 from the position of FIG. 14 to the position of FIG. 12, the sliding members or blocks 31 each traverse the lower rung 29 of the ladder in opposite directions pulling with them the ends of the cable 24. This not only draws Vup the slack in the cable but stretches the cable somewhat within its elastic limit to bring the section 21V tightly together. No more is required to bring the ladder to its operative extended condition.

It should be observed that the pivot axis at 37 is below the pivot axes 35 at the ends of the levers when the levers a e in the condition of FIG. 12 applying tension to the cable 24. Thus the pivot axis 37 has moved to an overcenter position and the tension on the cables 42 tends to force the levers to remain in that condition. However, as indicated above, to prevent accidental dislodgment of the levers from the position of FIG. 12, a latch member 4-9 has been provided.

When the ladder is leaned against the wall, the enlarged portions of the rail formed by the hollow portions 23 should be facing the wall. When a person stands on the ladder, his weight applies a force in the direction of the arrow A of FIG. 5. This force is resisted principally by the aligners 653 each of which extend between three sections and, because of the overlapping forms a continuous column throughout the length of the ladder. Additionally the force may be resisted in part by a force couple having two hearing areas. The first hearing area is indicated by the arrows B in FIG. 5 and the second bearing area is indicated by the arrows C and comprises the force of abutting stud 55 against the strap 42 which in turn bears against the inner surface of the wall 57 forming a part of hollow portion 23.

It should be noted that the cable 24 actually plays no part in absorbing any of the force applied by a person standing on the ladder. Its main function is to draw the sections 21 together so that the ladder can be maintained in an erect condition for ease of handling.

When the ladder is to be made ready for storage or transportation, the positions of levers 34 and 35 are reversed to relax the tension on cable 24. Thereafter, the smaller or upper end of the ladder is rolled toward the lower end until it is coiled as in FIG. 3. The hook 83 is snapped over the nearest rung and the rolling of the ladder is completed.

We claim:

1. A ladder having a front side and a rear side comprising two spaced side rails,

transverse rungs longitudinally spaced along and fiXed to said side rails,

each said 'side rail comprising:

a plurality of short hollow sections each having a substantial depth from front to rear and having a first thin hollow portion and a second hollow portion rearward of said first hollow portion,

a plurality of flat braces disposed in said first hollow portions and pivoted at one end to alternate sections,

each said brace extending from the section to which it is pivoted across the adjoining section and into the succeeding section,

tensile means holding said sections together a stud projecting from second hollow portion of each section into the hollow portion of the adjoining section,

said stud being spaced from the rear surface of said second hollow portion,

and a guide strap passing through said second hollow portions between said stud and said rear surface.

2: A ladder having a front side and a rear side Vcornprisrng two spaced side rails,

' transverse rungs longitudinally spaced along and fixed to said side rails,

each said side rail comprising:

a plurality of short hollow sections' each having a substantial depth from front to rear and having at least a thin hollow portion, 4

a plurality of U-shaped cross section flat braces disposed in said hollow portions and pivoted at one end to alternate sections,

each said brace extending between at least two sections, and a tensioning cable passing within the confines of said U-shaped brace from one end of said ladder to the other.

33 A ladder having a front side and a rear side comprismg two spaced side rails,

transverse rungs longitudinally spaced along and fixed to said side rails,

each said side rail comprising:

a plurality of short hollow sections each having a substantial depth from front to rear and having at least a thin hollow portion and a plurality of U-shaped flat braces disposed in said hollow portions and pivoted at one end to alternate sectrons,

one leg of each said brace having a first projecting lug at one end thereof by Which it is pivoted to said sectron,

each said brace extending from the section to which it is pivoted across the adjoining section and into the succeeding section,

the other end of each said brace having a free projecting lug at the opposite end thereof normally overlying said -first projecting lug of the adjoining liner.

43 A ladder having a front side and a rear side comprising two spaced side rails,

transverse rungs spaced longitudinally along said side rails and being fixed thereto,

each said side rail comprising:

a plurality of short hollow sections normally in abutting relation, each section having a substantial depth from front to rear,

a stud projecting from a rear corner of each section into the adjoining section,

a flexible cable extending from the top of each rail to the lowermost rung,

said lowermost rung having a pair of Channels extending from end to end,

slidable members in said channels having the lowermost ends of each cable fixed thereto, and

a pair of levers pivoted at their lower ends to respecshoes-27 tive slidable members and pivoted to each lother intermediate their ends for applying tension to said Cables. 5. A ladder having a front side and a rear side comprising two spaced side rails,

transverse rungs spaced longitudinally along said side rails and being fixed thereto,

each said side rail comprising:

a plurality of short hollow sections normally in a'outting relation,

a flexible cable extending from the top of each rail to the lowermost ring,

said lowermost rung having a pair of channels extending from end to end,

slidable members in said channels having the lowerrnost ends of each cable fixed thereto, and

a pair of levers pivoted at their lower ends to respective slidable members and pivoted to each other intermediate their ends for applying tension to said cables,

said levers being adaptable to reverse their positions to cause said slidable members to traverse said bottom rung to apply and relieve tension on said cables,

the intermediate pivot passing to an overcenter position to when said levers are shifted to apply tension to lock said lovers in a tension applying position.

6. A ladder having a front side and a rear side comprising two spaced side rails,

transverse rungs spaced longitudinally along said side rails and being fixed thereto,

each said side rail compn'sing:

a plurality of short hollow sections normally in abutting relation, each section having a substantial depth from front to rear,

a stud projecting from a rear corner of each section into the adjoining section,

a flexible cable extending from the top of each rail to the lowermost rung,

10 cables.

7. A ladder having a front side and a rear side comprising,

two spaced side rails, transverse rungs longitudinally spaced along and fixed to said side rails,

each said side rail comprising, a plurality of short hollow sections each having a substantial depth from front to rear and having at least a thin hollow portion,

a pluralty of U-shaped cross section flat braces disposed in said hollow portions and pivoted at one end to alternate sections,

a transverse stud mounted in each brace intermediate the ends thereof,

each said brace extending between at least two sections, and a tensioning cable passing within the contines of said U-shaped brace and over said studs from one end of said ladder to the other.

References Cited by the Examiner UNITED STATES PATENTS 453,193 6/91 Kinser 182-163 609,281 8/98 Leach et al. 182-41 736,104 8/03 Hubbart 182-41 2,629,532 2/53 Tupper 182 163 3,070,188 12/62 Scruby 182-163 3,103,258 9/63 Scruby 182-163 .HARRISON R. MOSELEY, Primary Exmnner. FRANK B. SHERRY, Examner.

UNITED sTATEs PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 199 ,627 August 10, 1965 Quentin V. Wagner et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 7, line 12, for "ring" read rung line 25,

strike out "to", first occurrence.

Signed and sealed this 8th day of March 1966.

(SEAL) Attest:

ERNEST W. SWIDER ttesting Officer EDWARD J. BRENNER Commissioner of Patents 

1. A LADDER HAVING A FRONT SIDE AND A REAR SIDE COMPRISING TWO SPACED SIDE RAILS, TRANSVERSE RUNGS LONGITUDINALLY SPACED ALONG AND FIXED TO SAID SIDE RAILS, EACH SAID SIDE RAIL COMPRISING: A PLURALITY OF SHORT HOLLOW SECTIONS EACH HAVING A SUBSTANTIAL DEPTH FROM FRONT TO REAR AND HAVING A FIRST THIN HOLLOW PORTION AND A SECOND HOLLOW PORTION REARWARD OF SAID FIRST HOLLOW PORTION, A PLURALITY OF FLAT BRACES DISPOSED IN SAID FIRST HOLLOW PORTIONS AND PIVOTED AT ONE END TO ALTERNATE SECTIONS, EACH SAID BRACE EXTENDING FROM THE SECTION TO WHICH IT IS PIVOTED ACROSS THE ADJOINING SECTION AND INTO THE SUCCEEDING SECTION, TENSILE MEANS HOLDING SAID SECTIONS TOGETHER A STUD PROJECTING FROM SECOND HOLLOW PORTION OF EACH SECTION INTO THE HOLLOW PORTION OF THE ADJOINING SECTION, SAID STUD BEING SPACED FROM THE REAR SURFACE OF SAID SECOND HOLLOW PORTION, AND A GUIDE STRAP PASSING THROUGH SAID SECOND HOLLOW PORTIONS BETWEEN SAID STUD AND SAID REAR SURFACE. 